WHO lowers H1N1 vaccine projection, targets some for poor nations

Sep 24, 2009 (CIDRAP News) – The World Health Organization (WHO) today scaled back its estimate of how many doses of pandemic vaccine that producers will likely make over the next year and said it hopes to gather enough vaccine donations to cover about 10% of developing countries' populations.

Last week the WHO signaled that it would lower its estimate, which was originally 4.9 million. Today at a press conference, Dr Marie-Paule Kieny, the WHO's director of vaccine research, said the latest assessments indicate vaccine makers will make 3 billion doses over the next year, which would cover less than half of the world's population of 6.8 billion people.

These details about the WHO's efforts to collect vaccine donations for developing countries came the same day that the United Nations (UN) released a report detailing the urgent support needed to help developing countries respond to the pandemic.

Kieny said the WHO based its original estimate of global pandemic vaccine production on a survey it conducted in May of 26 manufacturers that indicated a willingness to make pandemic H1N1 vaccine. Some of the original assumptions weren't realistic, she said.

For example, yields from the original seed strain were about a third to a half that of typical yields for seasonal strains. Though she said new seed strains are producing better yields, they still aren't on par with what manufacturers get when they make seasonal flu vaccine.

Though dose-sparing assumptions were on target, the original estimate didn't take into account that manufacturers would also be producing seasonal vaccine for the Northern and Southern Hemisphere, Kieny told reporters.

WHO officials will conduct another survey among vaccine producers in October to refine its projection of global pandemic vaccine yield, she said.

Despite decreased projections, there are several promising vaccine developments, Kieny said. For example, a handful of countries, including China and the United States, have already approved pandemic H1N1 vaccines, and China is already administering the vaccine, with other countries, such as Hungary, soon to follow.

She also added that clinical trial findings showing that most people will need only one dose of the vaccine will help stretch the world's supply.

So far, China has immunized 44,000 people with the pandemic H1N1 vaccine and has received 14 reports of adverse events, she said. The effects so far are mild and similar to what health experts expect to see with the seasonal flu vaccine, she said, adding that some may not be associated with the vaccine.

The vaccine may need to be administered to millions of people to detect any rare but serious side effects, she said. If such events occur, they will need careful analysis to determine which ones are really related to the vaccine and which are coincidental, Kieny said.

Teams are already working on the logistics of distributing donated vaccine to developing countries, the WHO said in a press release today. The WHO said it has surveyed its regional and country offices to determine which countries have the greatest need for vaccine donations and initially will distribute about 300 million doses of vaccine to more than 90 countries.

In 2007, Indonesia's health minister raised awareness about pandemic vaccine sharing issues when she vowed to stop sharing H5N1 avian influenza samples unless countries developed a mechanism for sharing vaccine made from the samples with poorer nations that can't afford or don't have access to the shots.

Some pandemic planning experts have also said that pandemic vaccines for people in developing countries may help preserve the chain of supplies and services on which businesses in developing countries depend.

Two vaccine makers have already donated 150 million doses to developing countries, and on Sep 17 the United States and eight other nations announced they would share some of their vaccine supply as doses come available.

Kieny projected that the donations from the countries would total 50 million doses, though she said she anticipates that more countries will sign on to the donation push. She added that the WHO could round out the supply by purchasing vaccine from manufacturers that have offered a discount for developing countries.

Kieny said the WHO won't dictate how developing countries should set their priority groups to receive the vaccine, but she said it has strongly recommended that healthcare workers be first in line. However, she said that before vaccine is sent to the countries, the WHO will assess if the nation is ready to distribute the vaccine and if it has a plan to give it to priority groups. "No one wants it to sit in a warehouse," she said.

Developing countries will likely start receiving their first doses at the end of October or in November, Kieny told the media.

The United Nations, in its Sep 17 report posted today on the urgent support needed for developing countries, predicted that pandemic effects to poorer nations will include increases in poverty and hunger, increases in child and maternal mortality, and a strain on health services that are already burdened with treating diseases such as malaria, tuberculosis, and HIV.

The UN estimated the cost of providing the vaccines to developing countries at $600 million. Besides vaccines and other pharmaceutical measures to limit the effects of the pandemic, the UN report outlined measures that can strengthen developing countries' readiness, such as operational plans for vaccine campaigns and increased laboratory capacity.